The present invention relates to novel complexes of metals preferably transition metal and to processes for producing such complexes. The complexes contain at least one phosphorus center, and a carbon atom or an alkyl radical bonded to the metal to form a carbene or metal heteroatom alkenyl bond.
Currently there is increasing interest in complexes of transition metals having a novel structure. Potentially such compounds could have significant use in a number of applications such as chemical processing, herbicides, pesticides and possibly medical fields.
Recently there has been significant interest in the catalyst of Brookhart et al which may activate later transition metals in a polymerization process. Such complexes are disclosed, for example, in World patent application 96/23010 jointly in the names of The University of Carolina at Chapel Hill and E.I. DuPont published Aug. 1, 1996. The Brookhart et al patent application does not teach the complexes of the present invention.
The recent paper (Chem. Comm (1998) p. 849) by the coworkers of Gibson at Imperial College UK (and BP) teach complexes having a novel structure that is dissimilar to the complexes of the present invention. It is postulated the complexes of Gibson will have utility in the polymerization of certain monomers such as alpha olefins.
There has been a great deal of work recently by both Exxon in the field of metallocene chemistry and by the Dow Chemical Company in single site constrained geometry complexes. As far as applicant has been able to determine none of the chemistry proposed by either Exxon or Dow contain a carbene atom or a constrained alkyl carbon bonded to a transition metal.
There are several patents relating to amidinato complexes of transition metals which are suitable for the polymerization of various olefins. U.S. Pat. No. 5,502,128 issued Mar. 26, 1996, assigned to the University of Massachusetts, teaches such complexes may be used to polymerize vinyl aromatic monomers; and U.S. Pat. No. 5,707,913 issued Jan. 13, 1998, assigned to BASF, teaches such compounds may be used polymerize olefins. Neither of these patents disclose complexes of the structure of the present invention.
U.S. Pat. No. 5,557,023 issued Sep. 1996, teaches the use of some complexes of transition metals to oligomerize lower alpha olefins such as ethylene to higher olefins such as hexene and the like. The complexes of the patent do not contain a carbene atom or substituted carbon bonded to the transition metal.
Applicant has been unable to identify any prior art disclosing the complexes of the present invention. In short the complexes of the present invention represent a novel chemistry having potential applications in many fields.
The present invention provides a complex having the formula: 
wherein M is a metal atom; R1, R2, R3 and R4 are independently selected from the group consisting of a hydrogen atom, a saturated or unsaturated straight chained, branched or cyclic hydrocarbyl radical which is unsubstituted or substituted by one or more substituents selected from the group consisting of a halogen atom and a C1-6, most preferably a C1-4 alkyl radical; R7 and R8 are independently selected from the group consisting of a hydrogen atom, a halogen atom, an amide xe2x80x94NR1R2, imide xe2x95x90NR1, alkoxide or aryl oxide group OR1, and an xe2x80x94OSi(R1)3 group where R1 and R2 are defined above, and a saturated or unsaturated straight chained, branched or cyclic hydrocarbyl radical which are unsubstituted or substituted by a halogen atom or a C1-6 alkyl radical or a Lewis base (neutral coordinating ligands) which may contain a donor heteroatom including but not limited to ethers, tertiary amines, tertiary phosphines and cyclic amines; and each R5 is independently selected from the group consisting of radicals selected from the group consisting of saturated and unsaturated straight chained, branched and cyclic hydrocarbyl radicals, preferably C1-15 saturated or unsaturated straight chained, branched or cyclic hydrocarbyl radicals most preferably C1-8 straight or branched alkyl radicals and C6-12 cyclic aliphatic or aromatic radical; radicals of the formula Si(R6)3 wherein each R6 is independently selected from the group consisting of saturated or unsaturated straight chained, branched or cyclic hydrocarbyl radicals, preferably C1-10 saturated or unsaturated straight chained, branched or cyclic hydrocarbyl radicals; and radicals of the formula III: 
wherein R9, R10, R11 and R12 are independently selected from the group consisting of a hydrogen atom, a fluorine atom, a NO2 radical, a C1-6 alkyl radical, and a C8-12 aryl radical and E is an endocyclic nitrogen atom or a Cxe2x80x94CN group.
The present invention provides a complex dilithium salt of the formula II: 
wherein R1, R2, R3 and R4 are independently selected from the group consisting of a hydrogen atom, a saturated or unsaturated straight chained, branched or cyclic hydrocarbyl radical which is unsubstituted or substituted by one or more substituents selected from the group consisting of a halogen atom and a C1-6, most preferably a C1-4 alkyl radical; and each R5 is independently selected from the group consisting of radicals selected from the group consisting of a saturated or unsaturated straight chained, branched or cyclic hydrocarbyl radicals preferably C1-15 saturated or unsaturated straight chained, branched or cyclic hydrocarbyl radicals, most preferably C1-8 straight or branched alkyl radicals and C6-12 cyclic aliphatic or aromatic radicals; radicals of the formula Si(R6)3 wherein each R6 is independently selected from the group consisting of saturated or unsaturated straight chained, branched or cyclic hydrocarbyl radicals, preferably C1-10 saturated or unsaturated straight chained, branched or cyclic hydrocarbyl radicals; radicals of the formula III: 
wherein R9, R10, R11 and R12 are independently selected from the group consisting of a hydrogen atom, a fluorine atom, a NO2 radical, a C1-6 alkyl radical, and a C8-12 aryl radical and E is an endocyclic nitrogen atom or a Cxe2x80x94CN group.
The present invention also provides processes for the production of the above complexes comprising either:
(A) reacting a compound of the formula 1: 
wherein R1, R2, R3, R4 and R5 are as defined above, with a compound of the formula M(X)s(Y)t(L)n wherein M is as defined above, X is independently selected from a group consisting of an alkyl radical, preferably having from 1 to 10 carbon atoms which is unsubstituted or substituted by a C1-4 alkyl radical or a C6-10 aryl (e.g. benzyl) radical, a silylated amido or imido complex xe2x80x94N(Si(R6)3)2 or xe2x95x90N(Si(R6)3 where R6 is defined above, or imido xe2x95x90NR radicals where R is a C1-10 alkyl or a C6-10 aryl radical, Y is selected from the group consisting of a halogen atom, an alkoxy radical preferably having from 1 to 10 carbon atoms and aryloxy radicals preferably having from 6 to 10 carbon atoms, and the sum of s and t equal the valence of the transition metal M and provided that at least two of the X and Y groups can be eliminated from the molecule, L is a Lewis base as defined above and n is from 0 to 3; in a C5-12 hydrocarbyl solvent or a C2-10 ether solvent at a temperature from 20xc2x0 C. to 150xc2x0 C.; or
(B) reacting a compound of the formula II: 
wherein R1, R2, R3, R4 and R5 are as defined above, with a compound of the formula M(X)t(Y)s(L)n wherein M, L, s, t and n are as defined above, X and Y are independently selected from a group consisting of an alkyl, preferably having from 1 to 10 carbon atoms which is unsubstituted or substituted by a C1-4 alkyl radical or a C6-10 aryl (e.g. benzyl) radical, a silylated amido or imido complex xe2x80x94N(Si(R6)3)2 or xe2x95x90N(Si(R6)3 where R6 is defined above, or imido xe2x95x90NR radicals where R is a C1-10 alkyl or a C6-10 aryl radical, a halogen atom, an alkoxy radical preferably having from 1 to 10 carbon atoms and aryloxy radical preferably having from 6 to 10 carbon atoms, and the sum of s and t equal the valence of the transition metal M and provided that at least two of the X and Y groups can be eliminated from the molecule, in a C5-12 hydrocarbyl solvent or a C2-10 ether solvent at a temperature from 20xc2x0 C. to 150xc2x0 C.
The present invention further provides a process comprising reacting a complex of the formula: 
wherein R1, R2, R3, R4 and R5 are as defined above, and at least one of R7 and R8 are halogen atoms and the other may be a Lewis base as defined above, with a Grignard reagent or an alkylating or alkoxylating agent.